The present invention pertains to a drinking water purification system and, more particularly, to a modular system for under-counter or under-sink installation using replaceable cartridges and which may be configured in a system utilizing up to four cartridges, including a reverse osmosis (RO) cartridge.
A drinking water filter system adapted for under-counter mounting is shown in U.S. Pat. No. 6,436,282. The system is disclosed with three replaceable filter cartridges, one of which is an RO filter cartridge. The three cartridges are connected to a common header, but the dissimilarity between the three cartridges may require the use of a different attachment head within the header for each filter cartridge. Also, the header is designed for three cartridges, whereas it would be desirable to have a modular system utilizing from one to four filter cartridges, depending on the particular application.
It would also be desirable to have a modular system that could utilize from one to four separate filter cartridges, one of which could be an RO cartridge, in which the system could be assembled by the manufacturer or seller using identical filter heads and modularly connected mounting devices. Most cartridges could be provided with mounting arrangements and flow connections using the same head with the heads serially interconnected to form the desired configuration. An RO cartridge requiring a non-standard head could be designed for use in the modular assembly. It would also be desirable to have a modular system in which a proprietary fit could be provided that matches the filter cartridge to the head to assure proper fit.
The modular system described above, lends itself to an under-sink or under-counter system that is easy to install and provides easy cartridge replacement. Applying this modular design to the system of the present invention also provides the ability to utilize common filter heads with identical internal flow valve spindles that are controlled by attachment and removal of the filter cartridge, a simple and effective way of providing a seal between the spindle and the head, customizable key arrangement between the filter cartridge and the head that can be utilized to provide a proprietary feature for a seller and to assure use of the proper replacement cartridge, the ability to easily remove and replace the RO control valve in a special RO cartridge and head, and special assembly techniques that facilitate assembly of filter cartridges, including axially aligned inlet and outlet, color coded end rings and high friction end caps for facilitating cartridge replacement.